Never going to happen. It has been discussed before.All down to the possibility of "Pay2Win" bots, the idea of a user getting perks depending on their badges.This would be more-so used for Nitro users, but yet again, there is a counter argument.

Keep in mind, I'd like to have this on discord too, but hear me out.

Counter argument says why not add something to the Discord TOS to specify that bots are strictly forbidden to contain commands that are restricted for the usage of Premium Users, which is a rather good argument, and would work like all other Terms, by reporting to discord directly or them using algorithms of some sort to try judge if a bot is friendly or not towards TOS, users could also be warned on this, but due to it being something decently major to Discord's system and how they like to approach their users, it will probably be an instant de-activation of the account and then leading to termination after further investigation.

There is also the counter argument of "Well why would a bot owner make nitro specific commands? It doesn't benefit them?" This is a good point, but yet again, the minority will abuse it still no matter what.

In short, this wont be added for a long time, just because of the minority that will use it.